Change background color of cell in .Net Winforms DataGrid

Hi

Can somebody show me some example code that changes the color of a specific cell in a .net winforms datagrid?

I want to programatically change the cell color if it's a certain value
zattzAsked:
Who is Participating?
 
Mohammed NasmanConnect With a Mentor Software DeveloperCommented:
Hi,
 
  I just made quick conversion,  and used Employees table from northwind db to test it, and worked fine

uses
  System.Drawing.Drawing2D;

//
  type
  DataGridColoredTextBoxColumn = class(DataGridTextBoxColumn)
   protected
    procedure Paint(g: System.Drawing.Graphics; bounds: System.Drawing.Rectangle;
      source: System.Windows.Forms.CurrencyManager; rowNum: Integer; backBrush: System.Drawing.Brush;
      foreBrush: System.Drawing.Brush; alignToRight: Boolean); override;
  end;

// implementation

procedure TWinForm.TWinForm_Load(sender: System.Object; e: System.EventArgs);
var
tableStyle : DataGridTableStyle;
i, numCols : Integer;
aColumnTextColumn :  DataGridColoredTextBoxColumn;
begin
  bdpDataAdapter1.Fill(ds,'Employees');
  tableStyle := DataGridTableStyle.Create;
  tableStyle.MappingName := 'Employees';
  numCols := ds.Tables['Employees'].Columns.Count;

  for I := 0 to numCols - 1 do
  begin
    aColumnTextColumn := DataGridColoredTextBoxColumn.Create;
    aColumnTextColumn.HeaderText := ds.Tables['Employees'].Columns[i].ColumnName;
    aColumnTextColumn.MappingName := ds.Tables['Employees'].Columns[i].ColumnName;
    tableStyle.GridColumnStyles.Add(aColumnTextColumn);
  end;

  dataGrid1.TableStyles.Clear;
  dataGrid1.TableStyles.Add(tableStyle);
  dataGrid1.DataSource := ds.Tables['Employees'];

end;

{ DataGridColoredTextBoxColumn }

procedure DataGridColoredTextBoxColumn.Paint(g: System.Drawing.Graphics; bounds: System.Drawing.Rectangle;
  source: System.Windows.Forms.CurrencyManager; rowNum: Integer; backBrush: System.Drawing.Brush;
  foreBrush: System.Drawing.Brush; alignToRight: Boolean);
var
  c: WideChar;
  o: System.Object;
begin
  try
    try
      o := Self.GetColumnValueAtRow(source, rowNum);
      if (o <> nil) then
      begin
        c := string(o)[1];
        if (c > 'F') then
        begin
          backBrush := LinearGradientBrush.Create(bounds, Color.FromArgb(255,
                200, 200), Color.FromArgb(128, 20, 20), LinearGradientMode.BackwardDiagonal);
          foreBrush := SolidBrush.Create(Color.White);
        end;
      end;
    except
      on ex: Exception do
      ;
    end;
  finally
    inherited Paint(g, bounds, source, rowNum, backBrush, foreBrush, alignToRight);
  end;
end;


HTH

Best Regards,
Mohammed Nasman
0
 
zattzAuthor Commented:
I found the following C# code on http://www.syncfusion.com/FAQ/WindowsForms/FAQ_c44c.aspx#q745q
but I don't know how to translate it to delphi.net

[C#]
 
     public class DataGridColoredTextBoxColumn : DataGridTextBoxColumn
 
     {
 
          protected override void Paint(System.Drawing.Graphics g,
 
               System.Drawing.Rectangle bounds, System.Windows.Forms.CurrencyManager
 
               source, int rowNum, System.Drawing.Brush backBrush, System.Drawing.Brush
 
               foreBrush, bool alignToRight)
 
          {
 
          // the idea is to conditionally set the foreBrush and/or backbrush
 
          // depending upon some crireria on the cell value
 
          // Here, we color anything that begins with a letter higher than 'F'
 
               try{
 
                    object o = this.GetColumnValueAtRow(source, rowNum);
 
                    if( o!= null)
 
                    {
 
                         char c = ((string)o)[0];
 
                         if( c > 'F')
 
                         {
 
                         // could be as simple as
 
                         // backBrush = new SolidBrush(Color.Pink);
 
                         // or something fancier...
 
                              backBrush = new LinearGradientBrush(bounds,
 
                                   Color.FromArgb(255, 200, 200),
 
                                   Color.FromArgb(128, 20, 20),
 
                                   LinearGradientMode.BackwardDiagonal);
 
                              foreBrush = new SolidBrush(Color.White);
 
                         }
 
                    }
 
               }
 
                catch(Exception ex){ /* empty catch */ }
 
               finally{
 
                    // make sure the base class gets called to do the drawing with
 
                    // the possibly changed brushes
 
                    base.Paint(g, bounds, source, rowNum, backBrush, foreBrush, alignToRight);
 
               }
 
          }
 
     }
0
 
Eddie ShipmanAll-around developerCommented:
Personally, I wouldn't use the built-in datagrids for ANYTHING because of their limitations.
Try SourceGrid from here: http://www.devage.com/SourceGrid/SourceGrid_EN.html

Although it is written in C#, you can user th eassmeblies with Delphi.Net.

It is an excellent control with so much functionality.

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Eddie ShipmanAll-around developerCommented:
Oh, BTW, the new version is only .Net2 compatible so download one of the older versions here:
http://www.devage.com/SourceGrid/SourceGridVersions.html
0
 
zattzAuthor Commented:
For this project I have to use the .NET built in datagrid
0
 
zattzAuthor Commented:
Thank you so much Mohammed. I really appreciate it.
0
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